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<head><meta charset="utf-8"><title>compiler-builtins for aarch64 missing long double (not musl) · t-compiler/help · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/index.html">t-compiler/help</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html">compiler-builtins for aarch64 missing long double (not musl)</a></h3>

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<a name="245869255"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245869255" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245869255">(Jul 13 2021 at 18:44)</a>:</h4>
<p>I'm trying to fix a new link-time error when compiling <code>cargo</code> on <code>aarch64</code> for linux (but not musl). (It looks like the triggering event was a recent upgrade to <code>curl</code> library, and my guess is <code>cargo</code> never needed <code>long double</code> until <a href="https://github.com/curl/curl/commit/8a75224a6986a5742215e0e73e1ac0d3419eff43">https://github.com/curl/curl/commit/8a75224a6986a5742215e0e73e1ac0d3419eff43</a> landed.)</p>
<p><code>compiler-builtins</code> appears to add the <code>long double</code> support in its <a href="https://github.com/rust-lang/compiler-builtins/blob/a065660883407b85d847989e62eca259e1e1476a/build.rs">build.rs</a> when building for <code>aarch64</code>, but only for <code>musl</code>.</p>



<a name="245869428"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245869428" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245869428">(Jul 13 2021 at 18:46)</a>:</h4>
<p>Is there any reason not to remove the <code>musl</code> condition for that block on line 428, so these symbols are available to all  <code>aarch64</code> targets?</p>



<a name="245869695"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245869695" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245869695">(Jul 13 2021 at 18:48)</a>:</h4>
<p><span class="user-mention" data-user-id="116015">@Alex Crichton</span> - I think you would have some insight here. Is there a better zulip stream to ask this?</p>



<a name="245870129"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245870129" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alex Crichton <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245870129">(Jul 13 2021 at 18:51)</a>:</h4>
<p>uh as for zulip streams I'm not sure, as for why it's ignored everywhere except musl I'm also not sure. Most likely it was just never needed anywhere else. Ideally <code>curl</code> wouldn't require long double support, but I guess if it requires it now then it seems reasonable to me at least to include these intrinsics in compiler-builtins</p>



<a name="245870298"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245870298" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245870298">(Jul 13 2021 at 18:52)</a>:</h4>
<p>Thank you! I'll submit a PR.</p>



<a name="245975859"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245975859" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245975859">(Jul 14 2021 at 15:27)</a>:</h4>
<p><span class="user-mention" data-user-id="116015">@Alex Crichton</span> - I uploaded <a href="https://github.com/rust-lang/compiler-builtins/pull/429">https://github.com/rust-lang/compiler-builtins/pull/429</a> </p>
<p>Would you be willing to take a look and approve/merge if OK?</p>



<a name="245976150"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/245976150" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Alex Crichton <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#245976150">(Jul 14 2021 at 15:29)</a>:</h4>
<p>ah sorry but I no longer have time nowadays to help maintain compiler-builtins</p>



<a name="246018679"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/182449-t-compiler/help/topic/compiler-builtins%20for%20aarch64%20missing%20long%20double%20%28not%20musl%29/near/246018679" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Rich Kadel <a href="https://rust-lang.github.io/zulip_archive/stream/182449-t-compiler/help/topic/compiler-builtins.20for.20aarch64.20missing.20long.20double.20(not.20musl).html#246018679">(Jul 14 2021 at 20:52)</a>:</h4>
<p>No problem. Understood. <span class="user-mention" data-user-id="143274">@Amanieu</span> was a huge help. (Thank you, both!) The change is already published, and I have a rust-lang/rust PR in review to update to the new version. As long as there are no CI hickups, this is almost done, and hopefully resolves the issue!</p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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